The purpose of the CFAR Flow Cytometry/Cell Sorting Core (Core D), referred to here as the "CFAR Flow Core", is to provide specialized flow cytometry to all CFAR investigators, to foster multi-disciplinary interactions within the UCLA research community, and to promoter advances in AIDS research. The specific aims of the Core are to: (1) provide flow cytometry instrumentation and technical assistance for experiments; (2) consult on flow cytometry; (3) provide training in the use of flow cytometry instrumentation and procedures; (4) maintain the quality of all data produced from the laboratory; (5) facilitate convenient, economical data handling for the users; and (6) provide support services to users. The CFAR Flow Core, consisting of 1.7 FTEs and an annual budget of $128,500, operates within the framework of the overall UCLA Research Flow Cytometry Core Facility which maintain 5.1 FTEs and has an overall budget of $389,577. Equipment available in the laboratory to CFAR investigators includes two FACScans and two FACStar/plus cell sorters. Of particular importance to the UCLA CFAR is that both of the FACStar/plus cell sorters are housed and maintained such that they can be used for cell separation of potentially biohazardous specimens, thereby permitting sorting of cells from HIV-infected people and sorting of cultured cells infected in vitro with HIV. A safety protocol, implemented to ensure the protection of the operator and the researchers during cell sorting of biohazardous samples, including isolated rooms, barrier protection of the operator, meticulous machine maintenance, and periodic tests to verify aerosol containment. The efficiency with which the Core can offer sorting of HIV-infected specimens as an invaluable asset of the UCLA CFAR. Center investigators also have ready access to routine as well as sophisticated analytic flow cytometric techniques. Among the sophisticated techniques available that have been user by CFAR investigators are four-color immunofluorescence analysis, CA++ flux measurements and assessments of apoptosis. The supervisor, who has 14 years of flow cytometry experiences, assists investigators with advice on experimental design, assistance with obtaining specialized reagents, consultation on data interpretation, training of new users, and development of new flow cytometric techniques or modification of existing techniques to meet emerging research needs. The CFAR Core gives priority in assignment of time to projects that foster translational research and those that involve basic and clinical research collaborations.